In the hole, using Motion 3

In the hole, using Motion 3
by Mark Suszko on Mar 1, 2010 at 6:01:27 pm

Clent threw this one at me: make a plane surface with an infinity backdrop, picture a shot of flat desert and the sky beyond. I can do that. Now, client wants a hole or gap or canyon to open up in that flat desert floor. What I'm thinking is a lot of keyframing, using an intial "ground" plane plane (made in photoshop) with a triangular chunk missing from it, (trianglular to kind of force perspective more, though this will be in 3-d) and two triangular fill-in pieces on a separate layer that would match the "bite" taken out of the initial ground plane image. Using keyframing I can have those fold down like trap doors and maybe throw some kind of particle dissolve effect at them to make them look like they are collapsing into chunks, falling away. Another image plane below the first one, set at 90 degrees like the backplane of the "sky", would then be revealed to make the camera-facing part of the "chasm".

This could take me a while :-)

Is there perhaps a better or easier way to tackle this kind of setup?
If I was in a CG program I think I would use a displacement map to punch the hole, but Motion 3 is new to me. Thanks for any suggestions.